ISO 16534:2020 pdf download – Thermal insulating products for building applications — Determination of compressive creep.
5 Principle The compressive creep is determined by measuring the increase in deformation of a test specimen under constant compressive stress and specified conditions of temperature, humidity and time. 6 Apparatus 6.1 Loading device, consisting of two flat plates, one of which shall be movable, arranged so that they compress the test specimen in a vertical direction. The movable plate shall be guided in such a manner as to be self-aligning. The plates shall be capable of being loaded smoothly and without distortion so that, during the test, the static stress does not change by more than +5 %. 6.2 Measuring device (e.g. dial gauge), capable of determining the distance between the two plates, i.e. the deformation of the test specimen, to an accuracy of 0,01 mm. 6.3 Suitable damping measures, to ensure the effects of external vibration are minimized (e.g. a substantial foundation and anchoring of the apparatus support). Examples of the testing apparatus are given in Figure 2.
7 Test specimens 7.1 Selection of test specimens The test specimens for determining the compressive creep shall be taken from the same sample, with the same preparation as the test specimens used for the compression test as specified in ISO 29469. The method for selecting the test specimens shall be as specified in the relevant product standard. NOTE In the absence of a product standard or any other technical specification, the method for selection of the test specimens can be agreed between parties. 7.2 Dimensions of test specimens The thickness of test specimens shall be equal to the original product thickness. The width of the test specimens shall not be less than their thickness. Products with facings or integral moulded skins which are intended to be retained in use shall be tested with these faces or skins intact.
Test specimens shall not be layered to produce a greater thickness for testing. The test specimens shall be cut squarely and have sides with the following recommended dimensions: — 50 mm × 50 mm; or — 100 mm × 100 mm; or — 150 mm × 150 mm; or — 200 mm × 200 mm or — 300 mm × 300 mm. The dimensions of test specimens shall be the same as used in the compression test as described in ISO 29469. These are specified in the relevant product standard or agreed between parties. The linear dimensions shall be determined in accordance with ISO 29768, to an accuracy of 0,5 %. The upper and lower faces of each test specimen shall be flat and parallel with a tolerance no greater than 0,5 % of its side length, up to a maximum of 0,5 mm.